Pumps



March 15, 1966 A. A. ASHTON 3,240,151

PUMPS Filed Jan. 28, 1963 4 Sheets-Sheet 2 A/erz A. AM 2 0/7 (FM Vi ATTORNEVJ March 15, 1966 A. A. ASHTON PUMPS 4 Sheets-Sheet 5 Filed Jan. 28, 1963 United States Patent 3,240,151 PUMPS Albert A. Ashton, Dallas, Tex., assignor to The Youngstown Sheet and Tube (Iompany, Youngstown, Tex., a corporation of Ohio Filed Jan. 28, 1963, Ser. No. 254,285 4 (Ilaims. (U. 103-5) This invention relates to pumps, and more particularly to pumps especially designed to handle drilling fluid for wells at high pressure.

In recent years drilling for oil and gas has been carried out at ever increasing depths. It is not uncommon for wells to be completed today at depths in excess of 10,000 feet. All indications are that drilling will continue to be carried out at ever greater depths than is customary today. In fact, some wells are now being completed at about the 20,000-foot depth.

At great depths it is necessary to circulate drilling fluids under a head of pressure of many thousands of pounds.

The old simplex, duplex and triplex pumps which have been used for many years are not adequate to develop the desired pressure for deep well drilling. It has been proposed that these pumps be compounded both in parallel and in series to obtain the desired volume of fluid at elevated pressures. A serious difiiculty is encountered in compounding pumps due to the total pressure variations in each pump. When these total pressure variations reach harmonious conditions, the variations cannot be tolerated. For instance, a double acting duplex pump has a theoretical total pressure variation of 46%. One commercially available triplex plunger type pump has a total pressure variation of 23%. One quadruplex plunger type pump has a total pressure variation of 33%. One available sextuplex plunger pump has a total pressure variation of 14%. It will be seen that when these pumps are operating at high pressure that the total pressure variations in the output manifold, where pumps are compounded and reach harmonious conditions, can be tremendous. For instance, the sextuplex pump referred to above, which has a pressure variation of 14%, is designed to produce a pressure of 5040 pounds under maximum operating conditions. Thus, the total variations in pressure in this pump may be as hi h as 705 pounds. Obviously, if two or more of these pumps are compounded, the total pressure variation gives substantial problems.

The problems discussed above have been recognized in the industry. These problems may be met by using pulsation dampeners on the output manifold of the pumps. These dampeners, however, are a continuing source of maintenance problems. By way of example, one form of dampener permits the output fluid to act against a pressure-filled resilient bag which tends to smooth out pulsations. Obviously, the resilient bag which is subjected to as much as 5000 pounds of pressure when the pump is operating, and to atmospheric pressure when the pump is not operating, is not only an expensive auxiliary item for a mud pump, but is a constant source of maintenance problems. it is well known that a quintuplex pump has a theoretical total pressure variation of only 7%, which for most applications eliminates the need for dampening devices. Quintuplex pumps of conventional design are bulky and diflicult to maintain and are not generally used due to these and other considerations.

In order to save space, simplify the construction of the crankshaft and provide easy access to the cylinders, quintuplex and other multiplex pumps have been designed with the cylinders spaced radially around the axis of the crankshaft. However, these designs have been of the master and articulated connecting rod type and do not provide equal fluid flow characteristics from each cylinder because "ice of the dissimilar motions of the master and articulated rods. Pumps of this design also become objectionably bulky when sufficient articulated rod bearing capacity is provided for heavy duty service. The present invention employs a single-throw crankshaft with each connecting rod journalled individually on the crank pin, thus providing identical motion for each connecting rod and plunger, resulting in equal fluid flow and pressure characteristics for each cylinder, and with a minimum radial space requirement. With this invention it is possible to employ the quintuplex pump without the disadvantages noted above.

It is an object of this invention to provide a pump designed for use in pumping drilling fluids in which the theoretical total pressure variations are much lower than any pump presently available for comparable service.

Another object is to provide a pump designed for use in pumping drilling fluids in which the theoretical total pressure variations are much lower than any pump presently available for comparable service to permit compounding of pumps without the need for dampening devices.

Another object is to provide a pump for handling drilling fluids which is compact in design and has a relatively small percentage of total pressure variation in the output manifold.

Another object is to provide a compact radial pump for handling drilling fluids in which each plunger has the same speed characteristics so that the volume and pressure of fluid delivered by each cylinder will be substantially identical.

Another object is to provide a radial pump for use in oil field service in which the pump crankshaft is arranged for rotation about a vertical axis and both the intake and exhaust manifolds are located below the pump cylinders to give ready access to all portions of the pump and avoid the use of overhead piping which would interfere with the mobility of the pump.

Another object is to provide a radial pump for handling drilling fluid in which all parts of the pump which are subject to wear are easily accessible.

Another object is to provide a radial pump for drilling fluid service which will operate at a sufficiently high rpm. to permit direct connecting to suitable engines for driving the pump.

Other objects, features and advantages of the invention will be apparent from the drawings, the specification and the claims.

In the drawings, wherein an illustrative embodiment of this invention is shown, and wherein like reference numerals indicate like parts:

FIGURE 1 is a view in side elevation of a pump constructed in accordance with this invention;

FIGURE 2 is a view in end elevation of the pump of FIGURE 1;

FIGURE 3 is a top plan view of the pump of FIGURE FIGURE 4 is a view in vertical cross-section through the pump of FIGURE 1 with the drive section omitted;

FIGURE 5 is a partial top view of the interior of the pump shown in FIGURE 4 with parts broken away and in section to illustrate details of construction of the pump.

The details of the pump are best shown in FIGURE 4. The pump is seen to include a housing indicated generally at 10 in which a crank shaft 11 is mounted for rotation about a vertical axis. It will be noted that the crankshaft has only a single crankpin 12 to which the several plungers, only one of which is shown generally at 13, are secured. The crankshaft is driven by a bevel gear and pinion indicated generally at 14. As best seen in FIGURE 3, the several plungers reciprocate in cylinders 15 through 3 19, inclusive. From FIGURES l and 2 it will be seen that the cylinders are symmetrically arranged in spiral fashion about the rotational axis of the crankshaft 11.

The pump housing indicated generally at 10 preferably is primarily made up of a single casting 21. For convenience of access to the several parts of the pump, a plurality of access doors are provided in the side wall of the pump, such as door 22. A pan 23 provides a cover secured at the bottom of the cast housing 21 which may be removed for access to the underside of the pump and which provides a sump for collecting oil for the forced lubrication system. A gear case cover 24 completes the top of the housing and may be removed for access to the top of the pump and for removal of the crankshaft as will be more fully explained hereafter.

The entire pump assembly is preferably mounted on a skid indicated generally at 25.

While the pump might be designed to stand on end, it will be appreciated that this would result in variations, though slight, in the pressure delivered by each cylinder, and the accessibility of the several parts of the pump would be limited. A more primary reason for designing the pump to position the shaft vertically, however, is the conservation of space, particularly during transporting the pump between drilling sites, and stability. With the vertical crankshaft, no difiiculty is encountered in moving the pump through overpasses on a conventional fiat bed trailer.

The crankshaft 11 is uniquely suspended from a single thrust bearing indicated generally at 26. This bearing is mounted in a spider 27 which rests upon shelf 28 in the housing. The spider is secured to the housing by a plurality of bolts 29.

The single thrust bearing is assisted in maintaining the crankshaft vertical by a lower bearing indicated generally at 30. This bearing is of the type in which the rollers 30a are maintained in the outer race 36b while permitting the inner race 300, which is secured to the lower end of crankshaft 11 by plate 32, to be removed with the crankshaft. The lower bearing 30 is mounted in a lower bearing carrier 33 which is secured to the cast housing 21 by a plurality of bolts 34. From the description as it has thus far proceeded, it will be apparent that the crankshaft may be withdrawn from the housing by first removing all interfering structures and then removing bolts 29 and lifting the crankshaft vertically out of the housing.

As noted above, the crankshaft is driven by the pinion and bevel gear set 14. The bevel gear 35 is bolted to the gear hub 36 by suitable bolts 37. A counterbalance 38 is carried by the hub to assist in dynamically balancing the pump. The hub 36 is keyed to the upper end of crank shaft 11 by key 39. The hub is held in place by the retainer plate 41 which is secured to the upper end of the crank shaft by bolts 42.

The pinion gear 43 drives the bevel gear 35. The pinion gear is mounted on shaft 44 which is journalled in the bearing assembly indicated generally at 45 and 46. It is noted that the bearing assembly 45 and 46 is constructed as an integral unit and may be withdrawn and replaced by a comparable unit merely by removing bolts 47. As an alternative, the unit may be withdrawn from the housing and repairs made thereto.

From the description as it has thus far proceeded, it is apparent that after the top cover 24 and bevel gear 35 have been removed, access may be had to bolts 29 to release the spider 27 which holds the thrust bearing 26. When this has been done and the crankshaft released from the several plungers 13, it is apparent that the crankshaft may be readily removed and replaced or repaired. Of course, the counterweight 48 would be released from the crankshaft and leftin the housing when the shaft is pulled from the housing. Before pulling the shaft the Wrist pins 49 would be removedand the crossheads 50 pushed back into an out-of-the-way position. This would permit the connecting rods 51 tocome out with the shaft. With the shaft assembly out of the housing, the stacked connecting rods and shaft bearings may be removed one by one by first removing the member 36 and bearing 27 together with split ring 52 which holds the several connecting rods and bearings in place.

It will be appreciated that with the main shaft and all connecting rods out in one assembly that it will be very simple to replace worn connecting rod bearings and to gain access to the interior of the pump for replacing any worn parts therein.

The crossheads 50 reciprocate in a suitable cavity 52 provided in the housing. As shown in FIGS. 4 and 5, a plurality of vertically extending webs 53 are circumferentially spaced about the housing. At appropriate points the crosshead cavity 52 is provided by a bottom 54 and suitable side wall sections 55 and 56 carried by the webs 53. The cavity 52 when viewed from the crankshaft 12 is generally U-shaped with the opening of the U being at the top and the free ends of the legs of the U being somewhat closer together than the bottom of the U.

In order to provide a replaceable wear member in cavity 52, a suitable liner 57 fits within the cavity 52 and provides a surface 58 for engagement by the crosshead. The top extremity of each leg of the liner 57 is formed with a downwardly and inwardly inclined bevel as shown best in FIG. 4 at 59. A mating surface is provided on the undersurface of the spreader strap 61 which is positioned above the liner. Suitable bolts 62 secure the strap to the crosshead Wall supports 55 and 56 and as the strap is forced downwardly by these studs the wedge surfaces provided by surfaces such as 59 on the liner 57 and on the undersurface of strap 61 spread the liner and hold it firmly against the bottom 54 and side walls 55 and 56. There will be a standoff of about or A; of an inch between the strap 61 and the members 55 and 56 so that the liner will always be firmly held in position.

The crossheads 50 are suitably secured to plungers 13 as by the threaded connection indicated by dashed lines at 63. At the point of the connection 63 it is preferred to include a resilient splash guard 64 which extends radially outward from the plunger so that any leakage of mud in a direction toward the wiper seal 65 will be prevented from reaching the seal 65. These precautions against leaking mud are desirable to prevent abrasive fluids reaching the interior of the pump.

The plunger 13 reciprocates in a suitable seal indicated generally at 66 which will not be described here as this seal may take any desired form and such seals are well known to those skilled in the art.

Suitable manifolds are provided for conducting muds to and from the plungers 13. For instance, an intake manifold indicated gen-erally at 67 extends in a continuous circle about the lower extremity of the pump. Mud from this circular manifold 67 is delivered to the plungers 13 through suitable risers 68. Mud is supplied to the manifold 67 through an inlet pipe shown in FIGURE 1 in dashed lines at 69. In order to maintain a positive head on each plunger, the inlet pipe 69 preferably receives mud from a centrifugal pump indicated generally at 71.

Mud leaving the pump passes through the several outlet conduits 72 to a manifold 73 which extends about the pump immediately above the intake manifold. This manifold 73 is also a continuous circular manifold and mud from this manifold is delivered to the outlet connection 74 of the pump.

Power for operating the pump may be supplied from any desired prime mover through a plurality of belts to the multiple belt sheave 75 which is mount-ed on shaft 76. This shaft is supported in suitable journals 77 and 78 and is connected to drive shaft 44 through a suitable coupling 79. A belt drive indicated generally at 81 de livers power from shaft 76 to the centrifugal pump 71.

The pump is also provided with a suitable auxiliary oil pump for circulating oil from the sump 23 to the several moving parts of the pump to keep them properly lubricated.

It will be noted from a study particularly of FIGS. 1 and 2 that the pump of this invent-ion has a very low silhouette. This permits the pump to be carried on a conventional flat bed trailer. As the pump will deliver fluid at relatively high pressures with extremely low diiferences in output pressure pulsations, several of these pumps may be coupled together to provide a large volume of high pressure fluid when needed.

FIGURES l and 2 also show the advantage of placing the intake and exhaust manifolds below the several plunger assemblies so that the manifolds will not interfere with free access to the plunger assemblies. As the interior of the pump can be easily reached by removing the cap 24 and extracting the main crankshaft as hereinabove explained, adequate access from the top and sides is provided for repair of the pump.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A pump for handling drilling fluids comprising.

a housing having an upper access port with a cover thereon a crank shaft suspended vertically in said housing in a thrust bearing mounted in the top of the housing,

said crank shaft having a journal on its lower end which stabs into a bearing mounted in the bottom of the housing,

a bevelled gear on the crank shaft located adjacent said cover and a pinion gear below the bevel gear cooperative therewith to provide a right angle drive for the crank shaft,

said crank shaft having a single crank pin thereon,

a plurality of cylinders symmetrically spiralled about the axis of rotation of said crank shaft,

plunger means in each of said cylinders,

each plunger means including a crosshead,

and connecting rods connected to said crosshead by Wrist pins, each of said connecting rods individually journalled about said single crank pin, said journals stacked one upon the other and supported upon a shoulder on the cranktshaft at the lower end of said crank pin, said thrust bearing being releasably secured in the housing to permit upward movement of the crank shaft through said port upon releasing the thrust bearing from the housing and the crank shaft from the plunger means. 2. The pump of claim 1 wherein a plurality of inlet conduits extend downwardly from said cylinders,

an inlet manifold is provided below said cylinders and curved about said housing, said inlet manifold connected to said inlet conduits, a plurality of outlet conduits extend downwardly from said cylinders, and an outlet manifold is provided below said cylinders and curved about said housing, said outlet manifold connected to said outlet conduits. 3. The pump of claim 1 wherein U-shaped cross-head guides are provided in the housing,

a U-shaped liner is provided in each cross-head guide supporting and guiding said cross head, the free ends of the U-shaped liner having downwardly and inwardly inclined beveled surfaces, and a spreader strap is secured to the housing and has surfaces mating with said beveled surfaces on the liner and spreads the legs of said liner and holds it firmly in place. 4. The pump of claim 2 wherein means are provided for delivering drilling fluid under pressure to the inlet manifold.

References Cited by the Examiner UNITED STATES PATENTS 2,463,486 3/1949 Johnson 103-174 2,752,088 6/ 1956 Borgerd et al 230-187 X 3,065,901 11/1962 Neubauer 230-58 LAURENCE V. EFNER, Primary Examiner. 

1. A PUMP FOR HANDLING DRILLING FLUID COMPRISING, A HOUSING HAVING AN UPPER ACCESS PORT WITH A COVER THEREON A CRANK SHAFT SUSPENDED VERTICALLY IN SAID HOUSING IN A THRUST BEARING MOUNTED IN THE TOP OF THE HOUSING, SAID CRANK SHAFT HAVING A JOURNAL ON ITS LOWER END WHICH STABS INTO A BEARING MOUNTED IN THE BOTTOM OF THE HOUSING, A BEVELLED GEAR ON THE CRANK SHAFT LOCATED ADJACENT SAID COVER AND A PINION GEAR BELOW THE BEVEL GEAR COOPERATIVE THEREWITH TO PROVIDE A RIGHT ANGLE DRIVE FOR THE CRANK SHAFT, SAID CRANK SHAFT HAVING A SINGLE CRANK PIN THEREON, A PLURALITY OF CYLINDERS SYMMETRICALLY SPIRALLED ABOUT THE AXIS OF ROTATION OF SAID CRANK SHAFT, PLUNGER MEANS IN EACH OF SAID CYLINDERS, 